Author's Note: Yes, I'm back with a brand new crossover! More awesome SGA/NCIS awesomeness... well, it's a story at least! Can't believe it's finally done, I mean, could have written a few one-shots to get the fanfiction beast back in the cage, but there you go! Besides, don't think you guys would appreciate it as much!

For those just finding this story, it is the third in a series, but I don't think you absolutely need to read the ones before. There are some mentions of events in them, but you can get by without it, probably.

Um, it's set post-EATG in Atlantis, and mid Season 6-ish for NCIS

So anyways, here you go, and have fun!

Warning: Its a little darker than the other fics... mentions of torture throughout... some emotional whumping... some physical whumping... not much swearing, or at least, what I would consider serious swearing... let's go with semi-serious swearing

Disclaimer: If I owned them... wow, now that would be an awesome birthday present... hint hint

Author's Note, 19/05/11: The Polish in this story is now fixed, with the help of the amazing LadyKristina, who deserves a massive thank you! Also thanks to Sakra, who pointed out some things wrong with the fic... I fixed what I could without completely changing the storyline, but thank you for all your help, both of you! If you ever come back to read this, that is...

CROSSED BOUNDARIES

Chapter 1

"Rodney, move it!" Sheppard shouted, heaving the scientist to his feet as McKay slipped over once more on the wet road.

"I'm trying!" McKay snapped back. "But it's dark, cold and wet, and it smells!" A sharp crack, gunshots, filled the air behind them, and Sheppard felt the whiz of a bullet as it just missed.

"Christ!" McKay cried, ducking from the sounds. "Moving, I'm moving!"

He scrambled to his feet, and Teyla took him by one arm, hauling him along, both limping.

Ronon ran back to join Sheppard, raising his own gun – a Beretta, not his blaster.

"No!" Sheppard ordered, needing to shout above the deluge of rain that had drenched them the moment they had escaped the warehouse. "We need to get out of here!"

Ronon growled, but obeyed, spinning on his heels and taking off up the road, bullets dogging their steps. Sheppard followed, holding on tight to his ribs, trying not to let them jolt.

Teeth gritted, pain ignored, blood forgotten, they all made it to the end of the road. And all without getting shot.

Sheppard looked both ways – to the left was the city proper, bright lights and noise despite the hour and the rain.

John took off to their right instead, taking the lead now.

"What?" McKay gasped. "Shouldn't we… people?"

He was struggling to breathe, the run and the beatings combining to wear him down. Sheppard just shook his head.

"No passports, no ID, we'd be toast," he told the scientist, watching as ahead, car lights suddenly turned down the road they were on. John stumbled to a halt, a bad feeling in his gut.

The car sped up on seeing them, and that bad feeling got worse. "Shit. Come on!"

He ran forward a few paces, and turned down an alley, bullets flying as the car screeched to a halt.

Sheppard wasn't about to let his team get gunned down though. He turned another corner, hoping they could double back to the main road.

No such luck, with three men running towards them, guns up, a bit shocked at actually coming face to face with the targets they were trying to cut off.

His first shot took the middle one square between the eyes, dropping him like a stone. His second shot joined Ronon's second shot to down the last, and suddenly the way forward was clear, just like that.

Trying to ignore the bad feeling in his gut, Sheppard ran forward, his team hot on his heels. Ignoring the three men they had just killed just as uselessly as he was ignoring his gut, they turned right again at the next corner, heading back for the street.

Only to be stopped by another set of car lights, turning into the wide alley, back wheels almost fishtailing on the wet road.

"Shit! Back, back, back!" Sheppard yelled, spinning on the spot and nearly twisting his ankle as his injured leg tried to crumble. Ronon caught him and with silent thanks, they raced on, trying to dodge yet more bullets from the car chasing them.

Rodney and Teyla turned back into the smaller side alley, and Sheppard and Ronon jumped after them, the car all but brushing their feet.

Sheppard grabbed someone, he wasn't sure who, but whoever it was, he hauled them back around the corner for a third time. "Move it, back to the road!"

He quickly followed, but didn't start running just yet, instead pulling his gun up and shooting at the reversing car, aiming for its wheels.

Ronon joined him, shooting out the back window as the vehicle came closer and closer.

Bullet hit rubber, and the car hissed to a halt, the back scraping against the bricks of the building next to them.

John didn't stay to watch, pulling Ronon away and following McKay and Teyla up the alley towards the road.

This time he sneaked a peak around the corner. "Okay, people it is. Move it!"

They slipped out, trying to catch a breather, keeping to the shadows and a slow jog instead of the fast paced sprint they had managed to keep up for the last ten minutes.

Or they were, until another car skidded out onto the road, pedal down and obviously after them. And obviously with orders not to let them escape, whatever it took.

"Run!" Sheppard shouted as bullets again flew after them. He only just heard Rodney's muttered, "Don't these guys ever give up?"

They ran though, still keeping to the side, but there was no way they were going to outrun a car, and no convenient alley for them to duck down. The car caught up.

"Down!" John screamed at the top of his lungs, falling to the ground and ignoring the pain that flared around his ribs. The bullets slammed into the wall above them as the car flew past.

Sheppard jumped to his knees, shooting at the car as it slammed on its brakes and spun back towards them. Ronon's gun joined his, and then Teyla's, and McKay's.

And then John's gun clicked on empty just as blood splattered inside the car.

"Shit," he muttered, tossing the now useless weapon aside. He preferred his own anyway. "Move it, move, move, move!"

He got to his feet, ignoring the way his breath hitched and pushed Ronon on. His hand came away sticky.

He looked at it, trying to run and realise that his friend had been shot at the same time. It wasn't easy. He shook his head, and muttered the next realization out loud.

"This isn't going to work."

Only Ronon heard him, falling back slightly, and admitting, "It never was." He didn't show any signs of being shot, but then again, he rarely did. "We need to get in those crowds."

"We're not going to make it," John told him, unable to help the wince as a stumble jarred his whole left side. "The city's too far. We need a better plan." He looked around, and, seeing an option, pushed to the front, forcing his body to ignore the pain. "Come on, this way. I've got an idea."

"Haven't any of you left yet?"

The three of them – DiNozzo, Ziva and McGee – turned around as Gibbs spotted them all standing before the plasma. Considering he had told them all to go home…

DiNozzo was the first to turn back. "Just watching the news, boss. They found another body in Europe. That's the fourteenth, all dead from the same thing."

Gibbs walked over to join them, unsure why they couldn't watch this from home. Which was where he had told them to go. But he had to admit – to himself at least – his interest was piqued.

"The rapid onset ageing deaths?" he asked, joining them before the television. "Of course." It had been all the news in the two weeks. He shook his head but said nothing.

"They're calling it murder now," McGee explained.

"Well, this last guy didn't cut his own chest, or put himself in a dumpster before he died from… old age," DiNozzo reminded the probie facetiously, earning himself a scowl from the younger man.

Yeah, Gibbs didn't get that either. Murder was a definite possibility. But what? A disease, some kind of biowarfare? He knew from very recent and personal experience that viruses could do a hell of a lot more damage than the average person believed. But the spread –

No, not now. He turned away from the computer and moved over to his desk, forcing his mind away from a case for five minutes. This last one had hit a little too close to home for his liking, and now he needed some breathing space from investigation. Especially from investigating a case that was way out of his jurisdiction.

He grabbed his wallet and keys from the draw in his desk, and switched off his light, about to go home, drink a glass of whiskey and work on his boat. Yeah, that always managed to clear his mind.

That was, before his phone rang.

Sighing, he grabbed the cell from his pocket, not even looking at the number as he flipped it open and answered the damn machine. First thing to go off when he –

Pelting rain, shouts and gun shots met his ears, and he stood up straight, a look of worry passing over his face. Ziva, who had turned when the phone rang, hit DiNozzo on his back so they could all watch, could all know something was not quite right.

"Gibbs?" The voice didn't even give the senior agent a chance to greet them. "Gibbs!"

Gibbs had to admit, he was a little shocked. "Sheppard?"

More gunshots sounded out and he pulled away slightly from the loud, and apparently close bullets. "Sheppard, is that you?"

"I need you to use the number I gave you!" the colonel shouted in his ear, over the rain and gun fire, and shouts, and the sudden sounds of squealing tires. "Gibbs, can you hear me?"

"Are you back home?" he demanded instead, not understanding but remembering the need for discretion. "Sheppard, what the hell is going on?"

"No, I'm calling from the freaking…!" Sheppard trailed off in annoyance. "It's a long story, but I need you to tell the number that I called! Understand. I need you to use that – McKay, watch out!"

The gun shots suddenly sounded a lot closer, and if Gibbs had to guess, he would have guessed Sheppard was the one shooting. "Sheppard, what the hell is going on? Where are you?"

"Sorry, little busy right now," he snapped. "Just use the number! Tell him – Ronon! Shi-."

Suddenly a sharp explosion hit the phone on Gibbs' ear, and he had to pull away as a high whine came through, followed quickly by silence. Something had happened to the phone Sheppard was using. Or the colonel himself.

Gibbs swung into action. Chucking the cell to a panicked looking McGee, he barked a sharp order, "Trace it," before moving back behind his desk and pulling his draw open again.

"I think he lost the need for a title when he tried to blow us up," he told her, before turning back to Gibbs. "But it was Sheppard, wasn't it? What was happening?"

Tucked away safely at the back, he found the piece of paper he was searching for. Moving at a jog, he went for the stairs. "Just help McGee!"

He took the stairs two at a time, racing towards Vance's office – the most secure room in the building, besides MTAC. The secretary had gone home long ago, but he knew the director of NCIS was still in there, doing whatever it was he actually did.

He didn't bother to knock, just walked right on, interrupting Vance where he was bent over his desk doing paperwork.

"Doesn't anyone in this place ever go home?" Vance demanded, looking up with his perpetually annoyed face. "What do you want, Gibbs?"

Vance didn't waste time on small talk though, which the older agent appreciated. "I just got a call from Colonel John Sheppard. I need to use your phone."

"Who?" Vance asked, frowning. "Wait. The Atlantis guy? Why are they back on Earth?"

"No idea. I think someone shot the phone he was using before he could tell me." Gibbs grabbed the director's phone – the most secure line in the building, besides those in MTAC – and glanced at the piece of paper.

"Shot?" Vance shook his head. "So who are you ringing?"

"Sheppard gave me the number for some Air Force General who works in a department called Homeworld Security."

"General O'Neill, I know him. He briefed me on the Stargate Program," Vance remembered. "Wait, Sheppard gave you his number?"

Gibbs nodded as he dialled. "It's for emergencies. Sheppard called to get me to call O'Neill. For what, I don't know, his phone got cut off before he could tell me. But I think this counts as an emergency anyway."

The phone was ringing, and Gibbs stood up straight, waiting for the man to answer. It didn't take long.

"Yello?"

Not expecting such a laid back response from the man in charge of the defence of the world, Gibbs raised an eyebrow. "Is this General Jack O'Neill?"

There was a pause of heavy silence. "Who the hell is this?"

Yeah, this had to be him. "General, my name's NCIS Special Agent Gibbs. I was the agent on the marine hybrid case until you had me taken off it." That still rubbed. "I was also on -."

"Yeah, I know who you are," O'Neill snapped. "How the hell did you get this number?"

"Colonel Sheppard gave it to me just before we left Atlantis a few months ago."

The man hissed and something squeaked, like he stood up. "Please tell me you're on a secure line, NCIS Special Agent Gibbs."

"As secure as I can get on such short notice," he told the general wryly. He wasn't an idiot. "And I needed to talk to you asap. I just got a call from Sheppard."

There was another pause, though this time the silence was more stunned than anything. "You? Just got a call? From Sheppard?"

Gibbs hated repetition. "Yes. I don't know where he was, yet, but he was under attack. He at least had Dr McKay and Ronon Dex with him. And he got cut off before he could tell me anything more than to contact you."

There was the sound of things being moved around quickly. "Why the hell did he call you?" the general demanded. "No, it doesn't matter. I'm coming into NCIS. I'll be there in two minutes, don't go anywhere!"

O'Neill hung up without even a goodbye just as McGee banged into the room, DiNozzo and Ziva on his tail. They all looked a little shocked.

"Did you trace that number?" Gibbs asked as Vance got to his feet, obviously annoyed at being so out of the loop. But he remained silent as McGee looked between the two men.

"I did." McGee shook his head. "It came from a payphone. In Gdańsk. In Poland."

"Poland?" Vance demanded, sharing a look with Gibbs. "What the hell is Atlantis' top team doing in Poland?"

"That's not all," DiNozzo told them. "Gdańsk is where six of the fourteen rapid onset ageing deaths have been found."

"I knew you were paying too much attention to that," Gibbs muttered. But it meant something, it had to. He didn't know what yet, though, and it was already bugging him.

Apparently he wasn't the only one. Ziva looked around, and then crossed her arms. "So, what's the -."

A bright light suddenly filled the corner of the office, bright enough that Gibbs saw it reflected in the eyes of his agents, and spun, hand going to his gun. Again, he wasn't the only one, but the only one to actually pull his weapon was Vance.

The others recognised it though, having experienced it themselves four months earlier. And a second later they also recognised one of the people who emerged from the bright light of Asgard beaming technology.

Gibbs let go of his sidearm and moved forward, offering his hand and a small smile. "Mr Woolsey, it's good to see you again."

The commander of the expedition to Atlantis took his hand, but he didn't smile; instead his face was tense, worried. "Agent Gibbs. I would say I'd feel the same, except maybe if you hadn't called…"

He let the words go unspoken, but Gibbs understood. He dropped his grip, even as the other man gave a roll of his eyes. "Come on, Woolsey. We knew something was up." He offered his own hand. "NCIS Special Agent Gibbs. I'm General Jack O'Neill."

Gibbs had already guessed that, going by the stars on his shoulder. According to Sheppard, this man had saved the world a few times over. He grabbed O'Neill's hand.

O'Neill twitched his eyebrow. "Straight to the point then." He handed the agent a black device, and then chucked one each to DiNozzo, McGee and Ziva. "I can't explain here. You're coming back to Atlantis. Colonel Caldwell, we're ready."

A second bright light filled the room, and – slightly confused – Vance looked away, squinting from the intensity. When he looked back, he was alone.

"God damn Air Force," he muttered, sitting back down and grabbing his phone, determined to find out exactly where his agents were.

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